===================================================================
@@ -0,0 +1,66 @@
+/* Check that no unnecessary sign/zero extensions are being emitted. */
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+/* { dg-final { scan-assembler-times "extu.b" 2 } } */
+/* { dg-final { scan-assembler-not "extu.w" } } */
+/* { dg-final { scan-assembler-not "exts.b" } } */
+/* { dg-final { scan-assembler-not "exts.w" } } */
+/* { dg-final { scan-assembler-not "movu" } } */
+/* { dg-final { scan-assembler-not "tst\t#255" { xfail *-*-*} } } */
+
+int
+test_00 (unsigned char* x, char* xx, int y, int z)
+{
+ /* If x[0] / b is treated as a non-extended QImode subreg the zero
+ test will be a QImode subreg test, which is supposed to ignore
+ bits[31:8]. However, since the QImode memory load always sign
+ extends, it's also OK to test all the bits. Thus we don't want
+ to see a tst #255 here. */
+ int b = x[0];
+ xx[0] = b;
+ return b ? y : z;
+}
+
+int
+test_01 (unsigned char a, unsigned char b, int c, int d)
+{
+ /* 2x extu.b */
+ if (a == b)
+ return c;
+ return d;
+}
+
+int
+test_02 (unsigned char* a, unsigned char* b, int c, int d)
+{
+ /* 2x mov.b */
+ if (*a != 0 && *b == 0)
+ return c;
+ return d;
+}
+
+int
+test_03 (unsigned char* a)
+{
+ /* 1x mov.b */
+ return *a == 0;
+}
+
+int
+test_04 (unsigned short* a)
+{
+ /* 1x mov.w */
+ return *a == 0;
+}
+
+unsigned char test_05_var;
+int
+test_05 (int a, int b, int c, int d)
+{
+ /* Must not see sign/zero extension here. */
+ test_05_var = (a == b) | (b == c);
+ if (test_05_var)
+ return d;
+
+ return 0;
+}
Hi, This adds some known to work SH tests for PR 53987. Tested with make -k check-gcc RUNTESTFLAGS="sh.exp=pr53987-1.c --target_board=sh-sim \{-m2/-ml,-m2/-mb,-m2a/-mb,-m4/-ml,-m4/-mb,-m4a/-ml,-m4a/-mb}" Committed as r219110. Cheers, Oleg gcc/testsuite/ChangeLog: PR target/53987 * gcc.target/sh/pr53987-1.c: New.